Haemorrhagic enteritis of turkeys

出血性肠炎(HE)是幼龄火鸡的一种急性病毒性疾病,特征是突然发病,血便,死亡率不定,通常为高死亡率,还可以引起免疫抑制.血液从泄殖腔流出(图1),可在粪便中见到新鲜血液或黑粪症(图2).     

火鸡出血性肠炎

出血性肠炎(HE)是幼龄火鸡的一种急性病毒性疾病,特征是突然发病,血便,死亡率不定,通常为高死亡率,还可以引起免疫抑制。血液从泄殖腔流出(图1),可在粪便中见到新鲜血液或黑粪症(图2)。     

Necrotic enteritis in turkeys.

Three flocks of turkey hens (16,000 each) between 7 and 12 weeks of age experienced outbreaks of necrotic enteritis. Necropsy revealed a dilated duodenum and jejunum with mucosal surfaces covered with a diphtheritic membrane. Intestinal scrapings showed very few oocysts of Eimeria sp. Histopathological findings were compatible with necrotic enteritis but with deeper, more severe lesions than in broiler chickens. Clostridium perfringens was isolated by anaerobic culture from the intestinal contents. Mortality returned to normal after ampicillin or tetracycline was added to the drinking water.     

Bovine rotavirus in turkeys with enteritis

Rotaviruses are the main agents responsible for diarrhea in different animal species and for infantile gastroenteritis. These viruses have been isolated from various avian species and have often been associated with poult enteritis and mortality syndrome. Nevertheless, the knowledge of rotavirus infection in turkeys is scarce. Six group A rotavirus strains obtained from pooled enteric contents of diarrheic turkeys were isolated in MA-104 cell culture and typed as G(6)P(1), a typical bovine rotavirus genotype. Additionally, the electropherotypes showed a migration pattern identical to the Nebraska calf diarrhea virus, and the complete NSP4 gene phylogeny showed that all six strains segregated in the genotype E2. Taken together, these results point toward a cattle-to-turkey rotavirus transmission. As a conclusion, bovine-origin rotavirus can be found in turkeys, and this transmission route must now be considered for the improvement of the health status in turkey farms.     

Haemorrhagic necrotising enteritis in foals associated with Clostridium perfringens

Two foals aged 35 and 48 h from 2 Thoroughbred studs died several hours after developing clinical signs of depression, severe haemorrhagic diarrhoea and dehydration. Both foals had an acute haemorrhagic enteritis extending from the anterior jejunum to the terminal ileum which was characterised histologically by villus necrosis. Necrotic villi were surrounded by large numbers of rod-shaped Gram positive bacteria. Clostridium perfringens was recovered from the intestines of both foals and the isolates were considered to be C. perfringens type C. Other cases of diarrhoea were also observed in foals of the same age on these 2 studs, but the aetiology of these was not determined.     

Haemorrhagic enteritis in a dog associated with Clostridium sp.

Shortly after a dietary change to milk, a 4-year-old female Chihuahua commenced vomiting, developed diarrhoea and subsequently passed blood. Despite treatment with amoxicillin, this dog died 7 hours after the commencement of the clinical signs.     

Focal hepatic necrosis in turkeys with hemorrhagic enteritis.

Disseminated acute focal hepatic coagulation necrosis was present in 9 turkeys submitted from 5 outbreaks of hemorrhagic enteritis. The lesion was unaccompanied by inflammatory cell infiltrate, biliary hyperplasia, or pancreatic necrosis, all of which tentatively distinguish this lesion from that of turkey viral hepatitis. No inclusion bodies were found.     

Pathology of spontaneous hemorrhagic enteritis of turkeys.

Thirteen turkeys naturally affected with hemorrhagic enteritis were studied pathologically. The main gross lesions were splenomegaly and hemorrhagic contents in the gut. The main histological lesions were intranuclear inclusion bodies in largemononuclear cells in many visceral organs and in reticular cells around the sheathed arteries of the spleens and varying degrees of lymphocytic hyperplasia in most tissues. The inclusions were frequently present in areas of the lymphocytic hyperplasia. The large mononuclear cells with the inclusions frequently showed a degenerative change.     

Role of splenectomy in prevention of hemorrhagic enteritis and death from hemorrhagic enteritis virus in turkeys

Hemorrhagic diarrhea, gross hemorrhagic enteritis, and death caused by intravenous virus injection of hemorrhagic enteritis virus (HEV) were prevented in otherwise susceptible turkey poults by surgical splenectomy. The splenectomized poults produced anti-HEV antibodies, which indicated that splenectomy did not completely prevent replication of the virus. These results indicate that the spleen is necessary for the development of the intestinal lesions of this disease. The role of a toxic factor in this disease is discussed.     

Hemorrhagic enteritis in turkeys: purification and quantification of the virus

Two methods for purifying the virus of hemorrhagic enteritis from infected turkey spleens are described. One procedure utilized precipitation with polyethylene glycol, and the other consisted of trichlorotrifluoroethane extraction. Both procedures included sucrose-cesium chloride gradient centrifugation in the final purification step. The buoyant density of the viral fraction was 1.34 g/cm3, typical for adenoviral particles, and the size and morphologic characteristics of the virions observed by transmission electron microscopy suggested that the purified virus belongs to the family Adenoviridae. The biologic activity of the purified virus was titrated by inoculating 10-fold dilutions of the viral suspension into turkey poults. Mortality and hemorrhagic diarrhea proved to be inconsistent parameters of infection, and the degree of splenomegaly was proportional to the virus dose. The body/spleen ratio was the parameter selected for measuring viral activity, and the body/spleen ratio 50% was adopted as the unit for the titration of the virus. By using the same system it was demonstrated that the infectivity of the virus could be neutralized with antiserum produced in turkeys.